Dust-gap valve



Patented Jan. 27, 1920.

H. G. SLATER. Dusv CAP vALvE.

I APPLICATION FILED APR. 7. I9I9.

HORACE G. SLATER, OF LOS ANGELES, CALIFORNIA,

DUST-CAP VALVE.

Specification of Letters Patent.

Patented Jan. 27, 1920.A

Application filed April 7, 1919. Serial No. 288,398.

To all whom t may concern Be it known that I, Honncn Gr. Snaren, a citizen or' the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Dust-Cap Valve, of which the following is a specification.

My invention relates to a dust cap valve 'for pneumatic tires, being more particularly a cap which tits over the ordinary valve stem 'found on pneumatic tires, the cap being provided with a valve mechanism therein which seats against the upper end of the valve stem forming a tight closure against leakage of air from the tire, and the principal object of my invention is to produce a dust cap valve of the character described, of simple form and construction, which is neat in appearance, and which may be readily applied to the common forms of valve stems now commonly found on pneumatic tires.

Other objects and advantages will appear hereinafter from the following specification.

Referring to the drawings, which are for illustrative purposes only,

Figure 1 is a side elevation of a valve stem with a cap embodying my invention thereon.

Fig. 2 is a vertical sectional view of the device shown in Fig. 1.

Fig. 8 is an enlarged vertical sectional view of the dust cap.

Fig. 4 is an inverted plan view in section on line 4-4, Fig. 3.

Fig. 5 is an inverted plan vie-W in section on line 5 5, Fig. 3.

11 designates a common form of valve stem used on pneumatic tires, such valve stem terminating at its upper end iii an exteriorly threaded reduced portion 12, the valve stem being eXteriorly threaded as indicated at 13 and having a central bore indicated at 14. In the bore 14 is arranged the common form of check valve in which a valve member 15 is elastically held by means of a coiled spring 16 against a seat 17, the valve having a pin 18 on the upper end thereof which extends freely through the seat 17, and when the valve is in closed position, such pin 18 extends above the top of the valve stem a short distance.

20 designates the dust cap which is inte-- riorly threaded at its lower end as indicated at 21 to engage the threads 13 on the valve stem. The cap 20 is provided with a shoulder 22 formed therein whichshoulder is circular in form and having a central opening 23. 24 designates a cup formed of suitable metal, which cup has a circular flange 25 formed thereon which seats upon theshonlder 22, the cup being inverted and extending downwardly through the opening 23.

The cup 24 constitutes a valve member and contains an elastic engaging member, preferably rubber, indicated at 26 which is securely held in place by bending over the edge of the cup as indicated at 27. 28 designates a. coiled spring, the lower end of which engages the top of the cup 24 and the upper end of which engages a head 29, such head being exteriorly threaded to engage threads 80 formed on the inside of the upper end of the cap, such head being provided with atool slot 31 by means of which the head may be adjusted in the top of the cap to place a greater or lesser tension on the spring 28 which in turn exerts a greater or lesser tension accordingly upon the cup 24.

The cap is used in the following manner:

The tire having been pumped to the desired pressure in the ordinary manner, the check valve 15 would be closed, that is, the check valve 15 would be against the seat 17 and the pin 18 on the valve 15 would extend slightly above the top of the tire stem, all of which is well known to anyone skilled in the art. The cap 20 is then threaded onto the valve stem, and during this operation the rubber member 26 in the cup 24 rst comes in engagement with the pin 18, and as the operation is continued, moves the pin downwardly thereby unseating the valve 15, the rubber member 26 coming into contact with the upper edge or top of the v-alve stem and seating thereon thereby forming a tight closure against the escape of air through the valve stem.

As the cap is further screwed down into Vplace the pressure of the cap against the top of the valve stem becomes greater Y the valve stem heretofore referred to temporarily operates during the pumping operation.

It will be noted that with my invention it is not necessary to depend upon the extremely small and delicate check valve in the tire stem for retaining pressure in the tire, but that I depend upon the valve formed by the cap and the end of the valve stem for retaining the pressure in the tire.

It will be understood that the cap is made of Asuilirient length to cover the exposed portion of the valve stem and -that the cap will screw down against the nut usually placed on the valve stem against the inside of the felly as v'shown in dotted lines in Fig. 1.

I claim as my invention 1.A -In `combination with the valve stem of i a pneumatic tire having a check valve therein, a cap arranged to thread onto the stem, a circular shoulder formed on the inside oi said cap, a head 'threaded into the upper end of -the'cap, a coiled spring-in said cap, and a valve member on said shoulder Iengaged by said spring arranged to seat on the upper end of said valve and unseat the check valve in said valve stern.

2. In combination with the valve stem of a pneumatic tire having a check valve therein, a cap arran ed to thread onto the stem, a circular shou der formed on the inside of said cap, a head threaded into the upper end of the cap, a coiled spring in said cap, and a valve member on said shoulder engaged by said spring, said valve member consisting of a cup, and an elastic seating element in said cup arranged to engage the upper end of the valve stem and unseat the check valve therein.

3. In combination with the valve stem of a pneumatic tire having a vcheck valve therein, a dust cap threaded onto theupper end of the valve stem, a head threaded into the upper end of -said cap; ae-valve member'in said cap arranged to'seat on the upper end of said valve stem and unseat the valve therein, elasticlmeans *in Said capfabutting against said head for holding said valve member against the 'endkof l*the valve stem, andm'eans for retaining said valve member in said cap.

In -stimony whereof, I have `hereunto set'my handat Los Angeles, California, this 29th day of 'March, 1919.

*II/GRACE G. SLATER. 

